Labour, which is against elected police chiefs, claims the move will cost £25m.

The issue was the subject of a spat at Prime Minister's Questions, with opposition leader Ed Miliband saying the government had its priorities wrong while Prime Minister David Cameron said it would make the police more accountable.

Coalition agreement

Many Lib Dems are against the proposals for more than 40 elected police chiefs, wanting them to be phased in gradually, while some are opposed altogether to the plan.

However, the party's leadership has said the initiative - which was a flagship policy for the Conservatives when they were in opposition - will go ahead as it was part of the coalition agreement.

If we have to accept it, we are going to make sure we do in in the most appropriate wayLib Dem spokesman

A Lib Dem spokesman told the BBC's Political Correspondent Ben Geoghegan part of the reason for the delay to the elections date was pressure from party councillors facing re-election next Spring.

"Our key aims were to de-politicise this as much as possible," the party spokesman said. "If we have to accept it, we are going to make sure we do in in the most appropriate way."

Our correspondent said councillors were worried there would be too much focus on law and order in the local elections if they were held on the same day as police polls.

Next year the Lib Dems will be defending seats in more than 30 metropolitan English cities, where they performed very poorly in May and lost control of key town halls, as well as smaller district councils in England.

Local authority elections will also be held across Wales where, among others, the party is defending Cardiff Council which it controls in coalition with Plaid Cymru.

None of the three largest parties have said whether they will field candidates for police chiefs under their own banner, with the Conservatives reportedly considering backing suitable local independents.

'Waste of money'

Critics of the initiative say it will create a US-style system compromising police independence.

In Commons exchanges on Wednesday, Mr Miliband said the £25m additional cost of switching elections to November could instead pay to keep 2,000 officers on the streets.

"You are making a bad policy worse by wasting money," he told Mr Cameron.

The entire electoral process would cost £100m, he added, and the police commissioners would be earning about £120,000 a year at a time when 16,000 police officers were set to be cut.

"What did we see during the riots? We saw visible, effective policing," he added.

"Isn't the truth this is the wrong priority at the wrong time for the country."

But Mr Cameron said the cash for staging the elections would not come out of policing budgets and argued that savings would be made by abolishing the current police authorities - which oversee the performance of police forces and chief constables.

"Why is he (Mr Miliband) so frightened of direct elections so police become accountable?," he asked, saying Labour had previously backed directly elected police oversight but has since done a U-turn.

On the delay to the elections, Mr Cameron said it was "important to get this policy right so it works".

Two Conservative backbenchers accused Mr Cameron of giving in to the Lib Dems on too many fronts and demanded concessions on other issues including Europe and abortion.